| // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /// @assertion A logical boolean expression b of the form e1 && e2 shows that a |
| /// variable v has type T if all of the following conditions hold: |
| /// • Either e1 shows that v has type T or e2 shows that v has type T. |
| /// • v is a local variable or formal parameter. |
| /// • The variable v is not mutated in e2 or within a closure. |
| /// Furthermore, if all of the following hold: |
| /// • e1 shows that v has type T. |
| /// • v is not mutated in either e1, e2 or within a closure. |
| /// • If the variable v is accessed by a closure in e2 then the variable v is not |
| /// potentially mutated anywhere in the scope of v. |
| /// then the type of v is known to be T in e2. |
| /// @description Checks that if v is local variable or formal parameter, either |
| /// e1 or e2 shows that v has type T, but v is mutated in a closure, then b does |
| /// not show that v has any promoted type. Local variable case. |
| /// @author ilya |
| |
| import '../../../Utils/expect.dart'; |
| |
| var closure; |
| |
| class C {} |
| |
| class D extends C { |
| f() => closure(); |
| } |
| |
| f(var y) { |
| var x = y; |
| closure = () => x = new C(); |
| |
| x is D && x is D ? [x.f(), x.f() /*throws*/] : null; |
| } |
| |
| |
| main() { |
| Expect.throws(() => f(new D())); |
| } |